AUTHOR=Chen Lihua , Chen Bin , Zhu Qian-Hao , Zhang Xinyu , Sun Tiange , Liu Feng , Yang Yonglin , Sun Jie , Li Yanjun 

TITLE=Identification of sugar transporter genes and their roles in the pathogenicity of Verticillium dahliae on cotton

JOURNAL=Frontiers in Plant Science

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1123523

DOI=10.3389/fpls.2023.1123523

ISSN=1664-462X

ABSTRACT=<sec><title>Introduction</title><p>Verticillium wilt (VW) caused by <italic>Verticillium dahliae</italic> is a soil-borne vascular fungal disease that severely affects cotton yield and fiber quality. Sugar metabolism plays an important role in the growth and pathogenicity of <italic>V. dahliae</italic>. However, limited information is known about the sugar transporter genes and their roles in the growth and pathogenicity of <italic>V. dahliae</italic>.</p></sec><sec><title>Method</title><p>In this study, genome-wide identification of sugar transporter genes in <italic>V. dahliae</italic> was conducted and the expression profiles of these genes in response to root exudates from cotton varieties susceptible or resistant to <italic>V. dahliae</italic> were investigated based on RNA-seq data. Tobacco Rattle Virus-based host-induced gene silencing (TRV-based HIGS) and artificial small interfering RNAs (asiRNAs) were applied to investigate the function of candidate genes involved in the growth and pathogenic process of <italic>V. dahliae</italic>.</p></sec><sec><title>Results</title><p>A total of 65 putative sugar transporter genes were identified and clustered into 8 Clades. Of the 65 sugar transporter genes, 9 were found to be induced only by root exudates from the susceptible variety, including <italic>VdST3</italic> and <italic>VdST12</italic> that were selected for further functional study. Silencing of <italic>VdST3</italic> or <italic>VdST12</italic> in host plants by TRV-based HIGS reduced fungal biomass and enhanced cotton resistance against <italic>V. dahliae</italic>. Additionally, silencing of <italic>VdST12</italic> and <italic>VdST3</italic> by feeding asiRNAs targeting <italic>VdST12</italic> (asiR815 or asiR1436) and <italic>VdST3</italic> (asiR201 or asiR1238) inhibited fungal growth, exhibiting significant reduction in hyphae and colony diameter, with a more significant effect observed for the asiRNAs targeting <italic>VdST12</italic>. The inhibitory effect of asiRNAs on the growth of <italic>V. dahliae</italic> was enhanced with the increasing concentration of asiRNAs. Silencing of <italic>VdST12</italic> by feeding asiR815+asiR1436 significantly decreased the pathogenicity of <italic>V. dahliae</italic>.</p></sec><sec><title>Discussion</title><p>The results suggest that <italic>VdST3</italic> and <italic>VdST12</italic> are sugar transporter genes required for growth and pathogenicity of <italic>V. dahliae</italic> and that asiRNA is a valuable tool for functional characterization of <italic>V. dahliae</italic> genes.</p></sec>